A lithium-sulfur battery cathode is sulfur, and a lithium-sulfur battery anode is elemental lithium. During electrical discharge process, the elemental lithium loses electrons to become lithium-ion, the sulfur reacts with the lithium-ion and the electrons to produce sulfides. A reaction equation is expressed as follows: S8+16Li++16e−1=8Li2S. A lithium-sulfur battery has advantages of low-cost, environmental friendliness, good safety, and high theoretical specific capacity.
However, since sulfur is electrically insulated, during charge and discharge processes, a volume of the sulfur will shrink or swell. In addition, the intermediate products of the sulfur formed in the discharge process, such as Li2Sn, n=4˜8, will be dissolved in an electrolyte, losing the sulfur, and a “shuttle effect” will occur between two electrodes. Thus the specific capacity and cycling stability of the lithium-sulfur battery will be limited.